Jargon busting: software

In a new regular feature I will try to translate a few technical terms into plain English. In the first post I will look at some terms about software that you may have seen.

Freeware
Software that the authors retain the copyright for, which is free to use for an unlimited period. The term has come to refer to any free software, such as public domain and open source.

Shareware
Software that can be used for free for a limited period, after which the user will have to pay to continue using it.

Public Domain
Any software that is free to use, which the authors do not retain copyright over.

Adware
Software - free or otherwise - that displays advertisements to generate income for the authors. This type of software often contains spyware.

Proprietary
Technically, any software for which the creator retains copyright or has a patent etc. Generally it used to refer to any software which can only be used with limitations.

Source Code
The actual code authored in a programming language (such as Visual Basic or C++).

Compile/Compiled/Compilation
In order for a program to be used by a computer it has to be compiled from the source code into machine code which the computer can understand.

Executable
A computer program, which is compiled from source code. On Windows these files generally have the extension .exe.

Open Source
Software for which the source code is made available along with the compiled executable.

Some of these are legal terms, others may have meanings that are in dispute. I have tried to give a simple explanation for them to help the non-computer-initiate and as such I have avoided any controversies. Nevertheless, feel free to comment on any of the terms used.

For more technical descriptions of these terms try searching for them on Wikipedia or Google.